Personally I would never pay more than 50 cents to a buck USD a roll for expired color film especially if I had no sense of how it was stored, particularly for high speed stuff.
If you would pay €2 for expired film but you could buy new Fuji Superia 800 / 24 exp. for €3.25, which would you buy?
Freestyle has 4-packs of Superia on sale for $16.00. Do the math, that comes out to €3.25 per roll.
I'm sure if you search your usual local sources, you can find comparable prices.
It depends on what you are looking for. The question is mostly if you like (or at least are willing to accept) the unpredictable results of expired high speed film. Expect color casts, base fog, both or none of these. I would not get these films expecting great results for half the cost of fresh film.
You need to remember one rule with film, the faster the speed rating the faster it deteriorates. Generally films that are 100 speed and slower, can, if properly stored, last a fairly long time, after they expire, especially B&W films. Higher speed films like 200-400, if they have been properly stored and are just expired can be okay. Ultra speed films, like 800-1600, can have colour shifts and fogging, even though they are just expired and have been properly stored. If your buying film from some clown on the Internet, you have no idea whether it has been properly stored, no matter what they say (people can and do lie).