Even if it costs more than your budget, I would buy a 5G phone. You are going to have this phone for years to come and there's no reason to buy old technology and regret that option later. I have had a Samsung S9 for the last 2 years and in the next year or 2 will likely replace it. I'm OK with 4G now, but in a year or so the 5G coverage will be much more widespread and I will want to be able to take advantage of that.
I believe it's the lasted Samsung S10 that has 5G and I highly recommend their products. We were able to buy 1 and get 1 free so the cost came out to be $350 per phone.