Making passive 1x probe so that capasitance is low and resistance is high there is real problem. It is nearly impossible.
Ok, there is some old 34MHz model what have 32pF / 1Mohm (Tek P6101A01. (I have not seen under 1m cable what still may be littlebit better) Perhaps also some others nearly this.) Also current Agilent N2870A is 1x and 1M, 39pF
But if it can be other than 1x but still useful with low levels, example 2x, situation is totally different. Example:
Attenuation 2X Bandwidth 500MHz, Input Impedance at the Probe Tip 2 M?, 12.7 pF, Cable Length 1.3 m. (Tek. TPP0502)
This is best passive probe with low voltage divider ratio and "high Z" input what I know.
(but also it is not cheap. Good probes are not cheap. One probe and you can buy 2 entry level DSO) (also 12.7pF is some high for 500MHz, but this is 2x probe)
So, if break this 1x, 10x, 100x etc "rule", it may give some more.
But who want 1.27x probe or 1.57x probe. So, who want make these. No one.
(some scopes have fine adjust for probe factor)