i have received some "special offer" to buy links on some PR7 pages in the past few weeks, nothing unusual about this, I get such offers all the time. The unusual part of the offer is the prepayment for 6 months or 1 year the vendor was demanding. Neither of the vendors want a monthly subscription payment. Why I will not be rushing to accept this offer is the fact that the pricing of the link is based on PageRank rather than the traffic this site could deliver. From experience you do not get a refund or discount when this sites lose their PR which is exactly what happened to a link I bough two months ago, it was PR6 at the last PR update its gone down to PR4.