options to strengthen backlinks

Hi Guys,
I have around 50 money sites for which i have created one way backlinks through whitehat methods. So each money site has an average of 500 backlinks. Now I want to strengthen the backlinks by pointing fresh backlinks to these tier 1 backlinks. As you can see, the total number of tier 1 backlinks I have is around 25000 and I am targetting to point around 100 backlinks to each one of them. That requires a huge number of backlinks generation approx (2500000).

What I am looking for is advice on what tool or service to use to generate this huge amount of backlinks.

1) Scrapebox service - can somebody recommed an economical service.
2) Xrumer service - can somebody recommend an economical service.
3) Bookmarking demon - i dont know if anyone provides bulk service.
4) Bulk blog creation - i dont know if any tool or service can create that many blogs on free web 2.0 properties.

Any help would be deeply appreciated.

Whatever you do, keep up a constant flow. Don't just blast everything once and then forget. If you really want 2.5 million backlinks, its way better to get 13888 per day to your 25k tier 1 (around 1 link every other day each) for a half year, than it would be to blast them all at once.

I'm considering rankuply (though I can't recommend them because I've never used them before) but they're $79 per month for 5k backlinks a day. Seems to me that if you buy 3 subscriptions, you've got 15k backlinks a day (2.7 million over 6 months) and it would cost $237 a month, or a grand total of $1422 for 6 months. Just a thought.

thanks so much for taking time to reply and suggest the service. rankuply looks promising.

i have shortlisted a few.

backlinkmassacre from bhw 85$ for 150000 comments
rankuply 79$ for 150000 comments
gigs at fiverr 50$ for 150000 comments

does anyone know of anyone who is cheaper than this.