Flying to Tuscany with a medical condition - preboard and perks questions

Preboarding does not give you an option to just randomly sit anywhere you want. (Except on Southwest. Southwest has no assigned seating so the earlier you board the more choice you have in choosing your desired seats when you get on the plane.) With other airlines, if you want a seat assignment you need to buy a ticket that allows you choose your seat when you purchase the ticket. If you aren’t willing to spend the money on a ticket that allows you to choose your seat upon purchase, you’ll be assigned (or perhaps choose from what is left) at check in.

Economy seats are in the back of the plane. First/Business Class is front of the plane. Usually a premium class in the middle. Then back of the plane is economy. (For international flights.)

Basic economy usually means you can’t choose a seat at purchase and may not allow a carry on. Its not that the seats in basic economy and regular economy are different, its just a way to charge you more to buy a seat assignment. It’s the same seats.

Preboarding is simply a way to allow those who may need more time to get settled.

Also , look at the plane’s seating plans. You will see that the front of the planes are first class, business, comfort +. Economy is in the back half of the plane. Basic Economy is usually the middle seats or non reclining last row.

Also be aware that Basic Economy has additional baggage fees and carry on limitations.
If you want better seats, you need to buy economy/main cabin. If you want to select your seats, you will pay extra for that too.

I've had a hard time finding a reliable source on the typical price difference between the two

Airline fares are in such a constant state of flux that what the 'typical price difference' might be is moving target, depending on what airline, what route , when the trip is and when you are looking at the fare.

Looking at airfares is more like looking through a kaleidoscope than a telescope.

The cheapest coach fares, almost certainly guarantee you will be in the rear of the plane. You will see the front half of the plane only when boarding and exiting.

Thinking ahead: since you are on a budget, look at monastery stays for cheaper hotel options. Research on https://www.monasterystays.com/ but book direct with the monastery. I have gotten better extended stay rates and better cancellation policies.

EDIT: Welcome to the forum. I hope our answers to your flight questions have not scared you off. Please let us know what your budget is. Also how mobile your relative is.

I don't see a lot of options for flights to fit what you want at a price you want. You said that $50 more ticket is workable. That's too low between class fares. Starting difference on United is at least $200, without seat choice surcharge.
( I only looked at United. Other airlines may be different,) Which airline are you considering?

Pre-boarding and seat selection are two completely separate things. If your companion needs to sit in the front of the plane and wants you to sit with them, you BOTH need to purchase seats in the appropriate category based on your airline’s seating plan. That means basic economy is out of the question, as that fare does not allow advanced seat assignment on most carriers.

As mentioned, most long haul planes Economy section starts about mid way through the plane. Generally around row 30 is when Economy starts. Usually right over the wings. Basic Economy generally means you have to pay extra for carry on bags and you don’t get “free” seat assignments. You may be able to pay to select seats in advance, but those seats will be economy seats, not in the front of the plane.

Pre-boarding applies to anyone that needs assistance boarding or needs extra time boarding. I’m not sure how it works with “basic economy”. That would be a question for the specific airline.

The price difference between Basic Economy and Economy is not thousands. Maybe a hundred or so? I’m sure it depends on the airline. For me it’s worth choosing my seat and not being last to board and potentially have no room for my carryon bag.

If your friend needs to be near the front of the plane it is costly. Business class and then premium economy are the seats you probably want and those are much more expensive. Basic economy is the seats that are left after everyone else buys their seats and you get assigned those at the airport and they will be in the middle in back. Regular economy will be the back of the plane but with the chance to buy seats.

Pre-boarding gives no special perks beyond getting on the plane first to get settled. Preboard is something you usually arrange at the airport and has nothing to do with seat selection. Your best bet is to talk to the airline about wheel chair boarding and see if that gives you what you want, but I doubt it.

Preboarding has nothing to do with seat selection unless you travel on southwest. The front of the plane on transatlantic flight automatically excludes economy seats. The front of the plane is first and business class. If one needs to sit in front, the s/he needs to buy a first cla$$ or at least business cla$$ seats, or upgrade using frequent flier mileage.

You can’t fly to Tuscany from North America, the flight to Tuscany will need to be from some other European hub. That flight is however short (no more than 2 hours).