I have the Bush Series C Manager's Desk with add-on. I got mine from Costco, which they're still selling depending on your location. It's at the top of your budget but it provides a lot of space and it's hardwood with sturdy construction. It's lasted me a really long time.
https://www.costco.com/bush-series-c-manager's-desk-in-mocha-cherry-finish.product.100072978.html