Hi SmokeDog,
If you're looking for cheap first & foremost, then I'd recommend the following:
Clickable
Marin Software
Acquisio (built mainly for use by agencies)
If paying ~5% of spend as a fee is acceptable to you *and* you spend $50K+/mo on PPC, then I'd also suggest:
Omniture SearchCenter
Kenshoo
Click Equations
I've been selling PPC mgmt solutions for 6 years now, and my one piece of advice to you is that with 30-50% inefficiencies existing in most PPC campaigns, buying based on price is a very bad idea given the opportunities for decreasing cost and increasing profits with a good, well-implemented solution - you should want to pay 5%+ for a solution, and you should shy away from vendors who drop their pants at the first hint of a sale, as things tend not to go well thereafter.
I love 3rd party paid tools, they are often great, while some of them offer really in depth account structures and refined budding strategics, most like Ominture are basic bidding tools, which help but sadly don't fully optimize the accounts but often are worth far more then the small % they charge.
I can add one more company to the list of recommendations:
Efficient Frontier
And disclosure I work for none of the companies listed, while I have clients that work with Omniture, as most of the time for clients we build them in-house programs to manage PPC for projects.
Omniture is one hell of a program if you are spending 50k a month... I'm looking for something that can help me spend 1k in advertising... You know how the saying goes... I'll spend a million to make a million and a penny. But starting off I need a cheap solution so I can focus on the business.
I'd prefer a software solution you can buy vs. a service.
In this case, I would definitely recommend using
PPC BidMax - by Apex Pacific
Its a low end entry level bid management software with autobidding option.
I'm not working for or associated with this company but have used their software in a previous role.
Hope it helps.