I tend to buy any gun I'm offered at the right price, and I never worry about what caliber it is.
Being in the farming community I do tend to get offered far more old .22" guns than .177" ones as .22" seems to have always been bought by farmers for pest control --- .177" being for bell targets and ladies.
I still prefer .22" as it's easier to get a .22" springer upto 12ftlbs, and to be honest at the short distances I tend to shoot at now there's little advantage in a .177's flatter trajectory.
All the best Mick