It honestly depends on volume. We split it into two categories: For 3 tables, slabs, or projects per month or less: Woodline USA part numbers 1394-1 and 1394-2 -1 for roughing work, -2 for finishing work, both run around $40 per bit and are solid carbide two wing bits with a ½ inch shank. As a perk those are made in Tennessee. If you're planning on more than 3 slabs per month, it’s totally worth it to get the bits with the replaceable carbide inserts Amana RC2255, RC2263 or similar bits work great, though the initial purchase is up over $150 once that is taken care of the replacement inserts are ~$30/ea and have four cutting surfaces to rotate through Generally, we stay with 2-1/2 inch diameter bits or less, though most of the 3+ HP routers can swing a 3-1/2 bit with proper precautions and experience. Start smaller and get comfortable with the RGS before jumping into that size bit.