Actually the IC design tools are a lot more expensive than 50k to 100k. You need a variety of tools for a modern process node (Calibre being one of them usually used for LVS/DRV - checing the GDS2 against the schematic and checking the process design rules). You also need a synthesis tool to convert RTL to a gate level representation (usually another 100k or so), a place and route tool (usually many 100's of K), simulators (probably around 50k again), tools for inserting test logic (again around 50k), timing analysis tools (probably around 50k again or more). Usually you have a bunch of timing analysis tools as you need to check timing at a variety of process corners and temperatures at the same time. There are also other tools that get used at various points in the flow that all seem to cost a lot of money too (like tools for analyzing static and dynamic IR drop and logical equivalance tools, formally checking that the gate level description matches the RTL)
So you can see you can end up spending a million dollars fairly easily.
