The good news is that there is a Modern U/R Delver deck that emerged on Magic Online that is about $165 in paper (as of 4/2019) that went 4-0 in a Modern Daily back in July 2015. It's still a solid list to consider now. Plus, the price is still about the same as it was in 2016!
Here is the list as piloted by Nielsen333 on Magic Online.
CREATURES
4 Delver of Secrets
4 Monastery Swiftspear
4 Young Pyromancer
NON-CREATURES
4 Sleight of Hand
4 Lightning Bolt
4 Remand
4 Vapor Snag
3 Peek
2 Forked Bolt
2 Lava Spike
2 Mana Leak
2 Mutagenic Growth
1 Dispel
1 Repeal
1 Spell Snare
1 Spell Pierce
LANDS
5 Island
3 Mountain
4 Steam Vents
4 Sulfur Falls
1 Shivan Reef
Lightning Bolt and Vapor Snag are the burn and tempo all-stars, respectively. Remand and Mana Leak are the primary counterspells. The rest of the non-creature spells are interchangeable with those in the sideboard. In the board there are: 3 Molten Rain, 3 Rending Volley, 2 Dispel, 2 Electrickery, 2 Negate, 2 Roast, and 1 Forked Bolt. This assortment allows the deck to adjust to many different kinds of matchups.
Also, like previous incarnations of Delver in Modern, the deck doesn't need fetchlands. Steam Vents and Sulfur Falls aren't exactly inexpensive nowadays, but they are certainly less than a playset of Scalding Tarns.
If you're looking for a budget Modern deck, this version of Blue/Red (U/R) Delver should be a great place to start.
Read more Magic the Gathering Modern articles here.