Buy a couple base cabinets, put on a back and new top. Can get used cabinets and tops at Habitat for around $20.
Have you looked at Ana Whites website? She has some fabulous designs. Attaching a link here, if this is not exactly what you want have a look around other options on website there’s usually multiple different styles.
Additionally a furniture piece like desks and dressers are commonly repurposed. My son used a desk to buld his.
Head over to Pinterest for lots of ideas —here’s one to give you a start
Get an inexpensive used kitchen cabinet and add a piece of butcher block (available for a lower than anticipated cost at Lumber Liquidators - and I thought they only sold flooring!) that extends beyond the edge for a breakfast bar. If you can't swing the cost or can't find an affordable cabinet and/or can't get an inexpensive butcher block top, you could use an old dresser and add a used table top to create a breakfast bar. You might have to add a base or add some risers under the top to make it reach counter height. If extending the top for a breakfast bar, be sure to add support brackets under the extended part.
Could also use an old table top to put on cabinets and can get decorative legs to create more stability for an eating area of the island if needed. Also don't think you have to have the cabinets lined up side by side they can be spread apart or create a corner area. I did the cornering of cabinets to create a trash can and recycle bins which are not visible from other areas of the kitchen. This also gave me a large prep area with seating for 5.