Ok here is suggestion. You DID mention saving some money. Ride around your neighborhood almost every brick home has a pile of bricks in back, my next door nieghbor had a pile of cinder blocks and pavers That I been lookin at for years. Use what ya can find for free and all ya gotta do is look and you can find it. put some of what ya find on the ground it aint gotta be perfectly flat or level either alls ya doing is building fire i=on it anyways. Do not morter it solid just lay them together. That way they can expand and contract as needed. They will last twice as long that way. Use what ya can find build it based on what you find. Whis is what I came up with for free.
If it falls apart in a couple years who cares its worth every penny I paid for it.