Often. I tend to buy my frames from eBay(sometimes at a quarter of the cost of High St opticians) then send them to a company in Nottingham called reglazemyglasses.com.
Nothing is too much trouble and they've gone out of their way to help(added 2mm of width on each lens once at no extra cost) in the past.
I generally get the glasses back in 6 days.
As a guide, I have single vision lenses with UV and anti scratch coatings, rimless, which are usually £39 a pair.
Hope that helps.