All depends on your budget!
Almost nothing given $25 in Birthday money is my net worth. Without estimating the value of my personal property, anyway.
I've been told by SIG fans that the HK price premium for more modern ones (I've been a fan of the P30 since a P30L V3 was my first experience firing a 9mm handgun.) is why they prefer SIG-Sauer overall. As a fan of the P938, MK25, and M11/P228, they have a point.
I might get a bolt action .308 under 6 pounds as per "Scout Rifle" technical specs first and foremost, but the MR556A1 and MR762A1, the weight due to import/export restriction in Germany and the Us forcing HK to have a pro-accuracy heavy barrel among other less consumer-friendly add-ons and missing features (I.E. True glow in the dark night sights due to the substances used in night sights being often radioactive, such as tritium, as far as my understanding of what tritium/German law is.) that make them both heavier than is ideal for a general purpose semi-auto, and bad for H&K internationally with its reputation for being more about its military contracts than its civilian market outside of Germany, and especially overseas, despite Colion Noir's opinion of the MR556 being favorable despite the weight.
Might look into the HK91 as per D5K's post, though. A SBR'd MP5 clone in 9mm (If the 91 is as per my memory a civilian legal limited import version of the MP5 as it stands as a modified G3 receiver on the "HK-slap" friendly design of both the MP5 and the G3 and its semi-auto equivalents for civilian use.)
The HK53 has been on my radar since reading about its use by Alaska's SWAT equivalent, however.