I bought a 4890 and I dont think my psu has all the connectors that i need. The XFX 4890 need 6pin and an 8pin . I unfortanately only have 2x6pin and a 4pin available which cant work. Can I buy any adapters ? If not, whats a good 40$ psu that definitely has these cables. Switching psu is a last resort!!!!
your best bet for an adapter would be an online store (newegg, tigerdirect, etc.,) or a microcenter
good & cheap rarely go hand and hand. here are some solid budget brands and series, brands will have PSU to cover the full spectrum of budgets so just don't buy a PSU because of the brand name only. Check the series too.