Cheaper alternatives to Big Y for refining a known intermediate Y-haplogroup (e.g. MyHeritage → YSEQ)?

I already have an intermediate Y-haplogroup from MyHeritage and I’m trying to refine it further without paying for a full Big Y (\~$450) if that is overkill for my goal.

Situation

* Intermediate Y-haplogroup is already known (MyHeritage). * I mainly need to test a specific downstream hypothesis / confirm a branch, not build a long-term matching database presence. * I’m aware that skipping Big Y means I won’t be in the FTDNA Y-DNA matching database and won’t get automatic haplogroup updates from FTDNA.

Idea I’m considering

* Use a targeted / second-round YSEQ panel (\~$99) based on the known intermediate clade. * Optionally upload results to YFull (\~€45) for interpretation / tree placement.

Questions

1. How good is YSEQ (targeted / panel / second-round testing) as a cheaper alternative to Big Y when the intermediate haplogroup is already known? 2. In which cases is this a sensible strategy, and when does Big Y still clearly win? 3. Are there other cheaper options I should consider for refining a known intermediate haplogroup (panels, single SNPs, other labs)? 4. If I do YSEQ + YFull upload, what practical limitations should I expect compared with Big Y (resolution, future updates, matching, tree placement)?

I’m not looking for a “best test in absolute terms” answer — more for cost-effective paths when the goal is hypothesis confirmation rather than maximum coverage and FTDNA matching.

Thanks.