I just ordered six pre-owned Blu-rays for a total of £25. (Taking advantage of two separate deals).
Blockbuster online customer reviews are not so great, but I thought it a worthwhile experiment at the price. Hopefully I won't receive notification of stock problems, scratched and unplayable discs, or bashed up cases.
Anyone used the online marketplace service? I'll let you know how I get on, but it'd be reassuring to hear some positive reports.