AITAH for reconsidering saying yes to my fiancé about his low-effort proposal?

I recently got engaged to my boyfriend of two years 4 days ago but now I’m having doubts and don’t know what to do. The first red flag was how the engagement happened. I would have loved if we had dressed up for a nice lunch or dinner before he proposed. Instead, he told me we had a private tennis lesson, so I didn’t dress up at all. Afterwards, he set up a “Marry Me” display—something he ordered from Amazon—by himself. I know it was from Amazon because when he cleaned it up, he put it back in the box and mentioned we should return it. On top of that, he chose a ring with a gold band, despite my having told him multiple times that I prefer silver. I didn’t talked to him about my distaste for the way he engaged to me because I know it will hurt his feelings.

Before we got engaged, we talked about having a very small wedding. When I brought up a small venue that cost $350 per hour to rent, he became upset and said he wasn’t going to spend $3,000 to $5,000 on a wedding and I’m acting entitled. When I asked him about when he thought we’d get married, he said he wasn’t thinking about that yet.

After thinking about how the proposal felt thrown together and pointing out that the wedding wouldn’t be as expensive as he feared, I’m wondering if I’m being entitled. Am I the asshole for challenging him on the proposal and pushing for a small, reasonable venue for our wedding?