I would like if you make subcategories on link sale if it's possible.. buying links | selling links | trading exchanging links you could do that also for sites, domains, everything.. it's easier to find what you need
For buying/selling links "Link Sales" and for trading-exchanging links "Link Exchange" forums are there and thats enough IMO. DON.
It might be easier to find what you need, but it would also litter the board with far to many sub-forums in BST (which as Shawn's noted in the past is not the primary purpose of DP). What might be even easier is just using the tools already given to you. There is already a separate link exchange forum, and you can already add WTB and WTS prefixes to link sales threads (and you can sort by them at the bottom of the forum).