I have 3 of them. A straight grip ejector gun with somewhat upgraded wood and a pistol grip non ejector in 12 gauge. I also have a 16 gauge non ejector. I like them (obviously) and don't find them clunky at all and the fit/finish is not bad at all on the ones I have. Can't say about the over/unders as I never held one. You can buy the SxS's in Canada starting at $200.00 for fairly used to around $500.00 for one like new with the average condition price of around $375.00. Except for 16 gauge. They are very hard to find here and go for quite a bit more if condition is there.
There's a 12 ga. straight gripped ejector described as VG condition currently listed at $650 in a well-known Canadian retail shop. In other words, you're bang on
