The Midland MXTA26 has a good reputation and is on sale for ~$40 right now. It’s an NMO mount antenna, but you also need to buy a base and cable for it. Probably the most common base folks get for it is a magnetic mount. I got the MXTA12 from Midland for that. I think it’s about $30, but it was a Christmas gift, so I’m not certain.