What's a decent price for you?
For summer, all I wear are plimsolls/deck shoes. You can get unbranded/box store version for as little as $5. Keds are also relatively cheap, and can be found between 20-70 dollars. I have two pairs of Sperry plims, one more like an Authentic, and one more like an Era, they ran $15 and $30 respectively. Vans are always good, and they have a good collection, however I find the Authentics NEED laces to worn comfortably, where as Keds and Sperrys can go without.
For boat shoes, I'd say hit up outlets, thrift stores and Winner's/Marshall's/etc.. A good pair of leather Sperrys will last a long time, but if you can find them for cheaper, why not get them cheaper, feel? Often times, you can get Sperrys/Sebagos at thrift stores that were made with much better care/materials. Remember to always go with simple colours and low profiles, I see far too many dudes wearing 'old man' boat shoes and they look ridiculous.
If you plan on doing something a touch more formal, get a low-heeled brogue/oxford in a lighter colour. I managed to get a pair of wingtip brogues for ~$2 last year, just some Rockports with a Vibram sole, but after a little buffing with some Bio-Oil, they came out real nice.