Wanted: Recommendations for qualified, reputable, REASONABLY PRICED guide in St. Petersburg

I imagine that a half day is the same price as a full day since that guide won't get another group that day and it's more a function of how much time you wish to spend. $100 for an all day tour guide-for a couple I presume-does not seem like an outrageous sum-is it? The OP's question reminds me of the "quality triangle" which says that one can have two out of three when it comes to price, quality, and speed (or other positive attribute), but not all three. What is REASONABLY PRICED in your view, OP?

We used toursbylocals.com in St Petersburg and were quite pleased. You might look at them, if only to get another idea of pricing. We ended up choosing a two day private tour for just the two of us that wasn't all that much more than the ship's group excursion. They also offer group tours. Our guide obtained the needed visas that were required. Our guide was Nikolai M and he was very good. Good luck.

Denny is correct. We also used www.toursbylocals.com and Nikolai and everything was great. We used him for Catherine's Palace in Pushkin, and he picked us up at our hotel in his own private vehicle. He was also the cheapest by far.

We've used toursbylocals all over Europe with great success.

I used tours by locals guides in both Moscow and Petersburg and was very pleased. For the same price as the tour from the cruise ship I had an all day tour in Moscow that was tailored to the two of us and perfect. In Petersburg, Nikolai took us to the Catherine Palace door to door from our apartment and it was again perfect. It was cheaper than the bus tours we had looked at locally; we were not on a cruise for that trip. Even if the cost is the same as the cruise tour, it is just better to have a private guide.

Hi,
Have you ever taken tours in Rome, Paris, London conducted by a 'qualified, reputable guide'? If you are 1 person or 2 of you, you will not manage much for $100, definitely not half a day.

The amount of people matter, also what you want to see. A promenade along the canals on foot, yes as a total $100 for the whole group, a guided visit to the Hermitage – hardly possible if tickets are included. There $100 will not cover even a party of 2 persons. And how long is that, 4 hours net time or including getting there and back? I doubt cruise ships charge so little. Their prices per hour only start at $100 for private tours, for some venues they are usually higher. Smaller operators charge less, or much less (depends on the size of the party) as their margins are smaller, but even then $100 for half a day per party is impossible. If per person, it'll depend on the venues and group size.
Let's take a quick look: you cannot walk the distance from the pier (a few miles away from the centre), so you need a vehicle driven by a professional, or you'd be happy with a novice running the risk of getting into an accident? The car needs to be clean, air-conditioned, as it can be quite warm in summer/or heated if we are talking of winter. The vehicle needs to be convenient (standard is Mercedes minivan where you sit higher and see everything through the large windows). By law the driver has to be licensed to offer services to passengers, which costs money, of course included into the rates. Also, how can you do the city tour on foot? You won't see anything, only a tiny bit.
Now what is more important, that is the quality of guiding. Here not only the ability to speak good English and keep the listeners' attention engaged are indispensible, but also the knowledge and manner of presentation. Guides, especially the required 'qualified, reputable' do not work for nothing (mind, $100 is not a lot in St Petersburg). They too have to be licensed and renew their permits for guiding in museums regularly (some museums require this every year), which costs hundreds of USD each season.
I believe, you do want to visit museums. Some charge a lot, and are still very difficult to obtain tickets to in the season (these include most of the palaces in the suburbs, the Hermitage, the Yusupov Palace where buying tickets on the spot is practically impossible). Unlicensed amateur will not even get you in, and certainly will deprive you of a lot of info.
Also do not forget about visas. You need them (c. $200 per visa from the USA) unless you do it via your ship or official local operator (then no visas). All arrangements must be done in advance.
Hope this gives you an idea.

Thanks, everybody, for taking the time to share your advice on St. Petersburg.

We have now acquired a private tour guide, driver, and van for two full days. The cost is around $250 pp for a group of 7. Tickets to sites are included. And yes, the price is lower than the cruise ships. Reviews of the company indicate an average of Excellent for more than 100 reviewers.
The tour Company (which issues a free blanket visa) is Anastasia. Google it. Talk to Katherine. She will help you plan your itinerary so that it suits you.

Sometimes I just don't understand people. You come here and ask for a recommendation for a tour guide. Not just 1 or just 2 but THREE people recommend Nikolai M and then you go book with somebody else...

Not that it matters to me - I hope you have a fabulous trip. But why do people ask for advice, get good advice, then they ignore the very advice they asked for.

My take is that Robert asked for suggestions, people responded, he reviewed the options, thanked them for their help, and made a choice that suited his needs. I hope it works well for you Robert. Safe travels!

Actually the company that pioneered this kind of tours, with passengers exempt from visa requirements, is Red October, still considered among the best both with regards to the quality of guiding and flexibility of the choices offered to the clients. Reviews on TripAdvisor and CruiseCritics prove it.