How to handle patents
The practical approach to handle these kind of situations is:
If you are aware of prior art that invalidates the patent, then ignore it and continue with your implementation. If the lawyers send a letter then you reply by pointing out the prior art. They will need to respond by defending the novelty of their patent and if it is clear cut, will avoid taking it further and having their patent overturned. This simply requires an exchange of carefully worded letters and need not be expensive.
If your argument is weak you will need to license the patent at a fair price. This can not be set artificially high and for a business is generally a fairly small proportion of profits. If it's hurting too much then look for a workaround carefully examining exactly the claims in the patent. There's usually another way given a little time (meanwhile you license and pay what you owe).
The idea that big companies can just win because they have clever lawyers is bunkum. They have a lot of patents to defend and a finite budget - especially if you are essentially "small fry".
Big companies use patents to defend themselves when entering a market with other big companies.