I would spend $$$ on the bra and shoes because you can NOT skimp on those (unless you lack boobs like I do).

Old Navy's activewear is great though. When I do any high impact activity, I NEED compression pants to hold my stomach in (thanks so much, loose skin) and those do the job. I often get them for under $5 when I shop the clearance racks and combine with sales/coupons. If there is an outlet near you, you can usually score last year's stuff for a couple bucks.

I adore my Panache sports bra - pricey but worth it to keep my 34DDDs still. See if these sites will ship to you - her room, bare necessities, fig leaves. I got one pretty reasonably ($50 instead of $70) by not being picky about color.

Ditto with sneakers - I view good sneaks as pain prevention. I got fitted at a running store, but if you don't have one, try this - www.roadrunnersports.com/shoedog - it asks questions to guide you to the type of shoe to try.

Ad I hate being sticky sweaty, so I love wicking fabric. Most of mine is from TJ Max or Marshall's, so not breaking the bank. My splurge wicking tshirt was on sale at LL Bean.

I agree with everyone as far as bra's and sneaks are concerned. My only two cents would be when it comes to buying athletic pants...I tend to by at least a size smaller than whatever I buy in regular pants/jeans because they tend to stretch.

Way to go you for running!