They should be good layers as long as they're in good health, and the person isn't lying about the age - when they say "1 yr old" is it closer to 12 months or 24 months?
I have two ISA Browns who are now 3 years old. Both stopped laying last fall and have not resumed at all. Just saying this so you know the highly productive breeds may not provide eggs for very long. As others have said, make sure of their age if possible, to gauge whether or not they will be productive and worth it. Not sure why mine stopped, but both seem healthy enough so far, and I don't intend to cull them. They can live out their lives here, even if they aren't producing anymore.
The 2 places I've gotten pullets from have gone up a bit since COVID. RSL pullets are $25 ea (20 weeks) & then the other place that sells a good variety are at $30-40 ea depending on age (6 weeks or 20 weeks). But everything is expensive in CT! I'd pay less the older they are.