As aluminum radiators go PRC has earned high praise, and in copper/brass Walker is the standard, and here in the west US Radiator comes close. Cost is probably always important for most of us (Roger is an exception, he walks down dark alleys with hundred dollar bills hanging out his pockets) but good radiators that won't give you continuing grief over the miles of driving you might do are worth something too.

This comment may be regional, so take it as such. It's getting harder and harder to find anyone that will repair any radiator (I have to go 22 miles to find a knowledgeable guy willing to do anything more than a swap out). It's double tough for aluminum, and then expand that imagination to being on the road in the middle of a town/county/state that you're not real familiar with. The advantage with the aluminum is almost any competent TIG welder "can" fix it, just whether they're willing to jump through the hoops is the question. Copper/brass might have higher odds of success.

That all being said, if you go for the Walker the most economical without doing hours of digging is through Speedway. They discount some on a normal case, and if you've got some time flexibility, when they run one of their $6.99 shipping promos you will save a bunch there. You could also look for someone who's cleaning out an extra they didn't use and get the private party "discount" but be aware that shipping can really hit there. I recently shipped a Walker in it's original packing (meaning big box with molded foam) to Texas and cheapest way (not counting Greyhound which, to me has an inconvenience cost) was $65. Dealers usually have shipper incented discounts that private party, infrequent shippers, don't enjoy.