I have found that once I do the math, many resale contracts are actually more expensive than buying direct from Disney, especially if the purpose is to add on to an existing contract. You need to compare the full cost of a resale contract (price per point PLUS closing costs PLUS MF reimbursements) to the cost from Disney. Also, most (but not all) contracts from Disney include current year points (fully bankable irregardless of normal banking deadlines) yet a number of resale contracts are missing some or all of the current year points.
For example, there is a 100 pt OKW contract on TTS, August UY, with the following: 100 points coming on 8/1/08 and 100 points coming on 8/1/09. Can close 5/6/07. No Annual Dues until 2008. Priced at $88 per point.
Total net cost would be approx $9,200 ($8,800 + $400 est closing costs), or $92 per point, and no 2007 MFs.
Direct from Disney, as long as you were to purchase by Mar 31, this will cost you $9,200 ($92 per point for OKW) plus no more than 10 mos maintenance costs of $365.83. HOWEVER, you will have 100 current year points, which you could use, bank or rent. I use an estimated value of $10 per pt ($1,000 total in this example), as it is pretty easy to rent them out at that price should you choose to do so. This brings your net cost to $8,565.83 ($9200 + $365.83 - $1,000), or $85.66 per point AND NO ROFR to worry about! Your offer would have to be approx $81.50 to EQUAL Disney's price!
Even assuming no MFs until 2008, the Feb UY is even worse, even though the price is $83, as there are no points until 2008 (net price approx $87 per point). In this case, you will have 196 more points by adding on direct, or a net "savings" over the resale contract of $10.94 per point!
Bottom line, adding on direct from Disney is still less expensive for you in both these instances. The only plus to these contracts is for non-owners - they can buy in at less than the minimum point requirement of Disney direct.