I have an opportunity to get a PR6 blog comment with no anchor text just the website hyperlinked. Is it worth it to buy? Good link juice or better spending money elsewhere?
it give your worth, overall it will helpful for your site to get higher ranking and maintain ranking
many people are doing link building in yahoo answering, they submit only URL not anchor text
Depends on heaps of factors: niche (relevant to your own?), n0/d0follow, number of links on the page, is the page itself PR6, position of the link on the page, price etc. You won't get anchor text benefit but you're still getting "juice" that will bulk up your ranking potential and filter down to your sub pages.