My signal is synchronous and has 150 mhz clock, so its quite fast.
I want to see its quality, and debug it.
I want the best for lowest money.
I will use standard probes that come with the product. I may change the physical configuration of the analogc probes for a thin needle type if needed.
If you want to really 'see' 150MHz signals, a 100 or 200MHz scope is far too slow. Attaching a probe is also going to disturb the signal.
What exactly is this 150MHz signal ? Is that 150MHz DDR (75MHz clock), or a 150MHz clock. Is that LVDS ?
If your 150MHz signal is synchronous, you already have a sampling occurring, and the
eye diagram of that sample is what actually matters.If you have a FPGA (seems likely) you can skew the clocks, and so sweep across the signal, to check the eye Tsu/Th.
By using the right tools, and approach, you can probably get by with an affordable 100~200MHz scope, but do not expect too much of
'see its quality, and debug it'Get the best sampling rate you can, as even with the highly slewed displays you will have, some phase measurements can be extracted, if you understand what you see is not an exact copy.
You will need to measure the timing margins, to sub-ns precisions, and you do not
need a scope to do that. Many FPGAs can do that inbuilt.