I attended an Israeli seminary over 15 years ago, so I’m not sure how relevant my experience is, but here it is: I personally felt that seminary was very helpful for me; I knew I’d be attending college, so I felt it was important to continue my Jewish education past high school also.
B”H I had a lot of financial aid from various sources, & used money from summer jobs to help pay for it. The seminary provided 3 meals/ day & I had relatives near the seminary so my other expenses were minimal.
I did attend a prominent “name” seminary in E”Y, because I felt it would be a more valuable experience for me; although I didn’t agree with everything the administration/ teachers said, I learned a lot from their views. Often disagreeing with a hashkafa shared by a teacher forced me to articulate (to myself) why I disagreed; this allowed me to either change my views or clarify them (or sometimes some of both).