Seller asked for more than listed price?

So a while back I messaged a seller about an item listed at $100 (originally $115 but dropped down to $100) and I asked if they would accept $90. They said no, that the item was "set at $100," so I said that was fine.

After we confirmed that we lived in the same area, they messaged me saying that they could sell it to me for $150 and to let them know when we could meet up.

What??????

That was a few weeks ago. The item is apparently still up for sale at $100 (hasn't changed at all) and I'm seriously considering asking them if they'd be willing to sell it to me but only for the listed price.

I'm still super irritated with this seller about this sudden change. I'm not sure if this is a scam thing or something?

I'd really like someone's thoughts on this because I really don't understand why they'd increase the price like that after I AGREED to pay their LISTED PRICE. I even asked if cash was okay and they said cash was fine!

However, there are other sellers in my area selling the same item for $150, but I'm not willing to pay that much yet and definitely NOT with THIS seller.