Just curious why are EOY contracts considered hard to sell. Personally I if I could get one for a "fire sale" I would consider it. I as well am considering buying additional contracts simply for points and a cheap EOY contract may be attractive to me given what I would assume be lower MF's.
The banking/borrowing of points doesn't work as well with EOY. If you have a 5,000 annual contract, you can book a 15,000 point stay with banking/borrowing. If you have an EOY, you could only book a 10,000 point stay. Also, you pay the club dues every year, whether you own EOY or annual.
People often buy EOY to get into the system. I did that. As I added more contracts, I became a much bigger fan of annual contracts. Now that I've decided I want to timeshare a lot less and spend more time cruising, camping and staying in nice full service hotels, I am actually down to 2 EOY Hiltons. They are opposite years, so I can still bank/borrow easier than someone with just one EOY, but I do still think a beefy annual contract is overall better for people who just want HGVC points. I have an affiliate that gives me a lot of affiliate benefits that are worth more to me than having Hilton points, though. If I didn't have a local affiliate with day use and bonus time available to me, I'd drop my 2 EOY and get a beefier annual contract (provided that I wanted HGVC points).
I have sold through the broker I listed above and my contracts took 6 - 12 months to sell with them being listed lower than other contracts for sale at the time.
Your other big issue with buying several EOY is of course, the extremely high closing/transfer fees for Hilton. The buy in of several cheap contracts could easily add up to more than one large contract after a few years when figuring all the closing fees and the multiple MFs. It really depends on how long you plan to own and use, though.