The LEGO Buyes Guide
As a collector of many years standing, and a buyer and seller on EBAY, I would like to offer the following words of wisdom to regulars and neophytes the world over.
1) I do not sell job lots as a rule on EBAY because of the prohibitive postage costs, likewise I buy most of my job lots from bootsales, or shop adverts. It tends to be that job lots online have already been raided for those specialist/themed bits that most people are looking for.
2) If you just want a big lot of general pieces do not pay over the odds, check how much you could buy say, a large creator pack for, and don't pay more than that. Please note that some people want to sell HUGE quantities which is usually OK. It is the up to 5 Kilos mob which are suspect generally as you tend to wind up with lots of base plates and 4X2 standard bricks or inclusions of MEGABLOCKS. The exception to this tends to be BIONICLE which is an unusual market, if you like building weird robots you can pick up some real bargains
3) If buying themed be aware that LEGO DO re-release certain large sets if the demand is high (generally in the themed sets) and WATCH for those ads which claim an item is no longer available. I have found items in my local TOYSRUS that even their web site said were out of stock, and have found items from local suppliers that were substantially under what people were asking for them online. ( and if JUSTretired sometimes at substantial reductions, so watch for the online speculators)
4) This is a GENERIC rule, small sets with lots of figures command higher prices than large sets with few figures. This is because of the number of people who collect figures only and then sell on sets with the figures removed. (This annoys me but does give opportunities to acquire sets cheap and then just get the figures, especially if the figures are common to more than one set). If the figs are specific and the set does not contain them then do not bother as to buy the figures separately will cost more than buying the set new (if it is still available).
Enjoy Your hobby and don't be afraid to ask reputable sellers for advice, most of us want to help people with their hobbies and meet like minded people.