I grew up in Victoria - at a time when whale populations were pretty low, so actually never saw any despite countless ferry trips to Vancouver or Port Angeles. Last year in May I had occasion to go back and spend a week and I took a whale watching trip. It was wonderful and out of the ordinary as at the end of the trip, one of the small 'wild' pods actually entered the narrows and went all the way to the Empress Hotel, put on a bit of a show and then left again. Made the news, for sure. I haven't done any other whale watching on the West Coast, so can't compare it, but in that area of water, the US and Cdn borders run pretty close....in fact my phone went to roaming part way through the trip...so sometimes tours overlap areas. If it matters to you, consider reviewing what the legal distance limits are between BC and Washington state. I know I chose my company, Eagle Wing, because of their ethical practices. (growing up in BC during the 70's left a strong ecological influence)
You want to decide which appeals to you more as far as type of vessel. The fast cigarette type boat may seem 'cool' but you need to wear provided gear for wet options, no covering during rain, bad for certain ailments - like neck or back issues - and if you want photography or are a bird watcher, have you too close to the ground. You want some height to get good views (though it can sway some making things challenging).
You want to also time your visit. Better viewing months for Victoria are May to Oct. For what it is worth, there are 'resident' and 'wild' pods of orcas. They act a bit differently, of course, but seem to be relatively easily identifiable by the companies.
My mom and I used to do day trips to Port Angeles so that is feasible from Victoria - or spend the most time in Victoria and head to Seattle for a couple of days - fly home from there. Victoria has the advantages of being in close proximity to other Gulf Islands (same chain as San Juan Islands) by ferry, Butchart Gardens, and if you like wild and can budget it, drive to Long Beach on the open mid island West Coast for a memorable night or two. Cheap version is Sooke's Point No Point. Western Vancouver Island puts you right out on the Pacific, wheras Victoria and up the coast to Port Renfrew actually sit in the Straits (seems they now call it 'The Salish Sea'), so there is land on the other side of the water. Up at Pacific Rim (Long Beach) you may just be able to watch pods of whales, sea lions right from your room with binoculars. Storms will be starting to come through providing its own majesty, and otter and seal play closer to shore. I am not sure whether you can get similar on Washington's Olympic Peninsula or not, but the west coast would be open to the Pacific as well.
As anywhere, you can get a variety of lodgings in Victoria. Classic hotels are expensive primarily due to the amount of conferences that take place. Coworkers have attended conferences on the cheap by booking AirBnB lodgings. There will be plenty of pied a terre type apartment short lets in James Bay, Dallas Road or around Cook St. All within walking distance of town and usually in converted old Victorian or Edwardian homes....but cheaper than the boutique B&Bs in the same neighbourhoods. Alternatively are cheaper tourist hotels in Esquimalt, Vic West or Tillicum areas. Then you take the bus or rent a car. The down side of being in 'downtown' Victoria is that the places readily accessible for short let apartments are in the trendy more affluent areas so groceries are more like Whole Foods than Safeway. James Bay does have a Thrifty Foods standard grocery store, so costs can be saved there.
For comparing, I guess you can only do some pricing research for Victoria, divide by the exchange rate and see what that buys in the US.