Hi lindseyr702,
There is nothing wrong with sorting and collating, but be more selective about what you buy. Lots and collections, sometimes called kiloware generally do not contain anything of real worth. There is of course the nice 'find' from time to time, but these are rare. If there is an auction house in your area that puts up stamp lots, you might try a check out visit. There you can see the stuff and decide how much it is worth to you before bidding.
A note about modern GB stamps. The market is saturated with these stamps due to excessive production by Royal Mail in such quantities and variety of presentation to leach as much money out of collectors as is possible. With a few exceptions the designs are awful. Many UK dealers have cancelled their contracts with Royal Mail because they can not sell the stuff and have found their stock to be near worthless. Be selective and buy the nice ones by all means, just don't pay too much for them. And don't regard them as an investment.
If you like GB stuff and sorting through stamps, you could consider specialising in the GB Elizabeth ll 'Machin' heads. There are legions of 'em so not for me personally, but you may have the talent, and above all, the eye for detail needed. A sample pack below. Click on the black 4d pics to embiggen.
Terry
Edited for error. TC.

