Upgrading your whip
Content: How to upgrade your whip with the best bang for your buck or Cost Effective Torture

Deciding whether or not to upgrade the whip you use in your prison can be a bit of a headache for the middle of the road coiner. Trying to gauge the cost with what gains you get is a bit of a challenge. This guide is for the person who has decided they are going to upgrade their whip and would like to get the most they can for their diamonds spent.

Whip Costs: The costs for the upgrades and added benefits are as follows:
Rattan: Free/comes with the prison for no additional exp boost or increased escape time
Soft Whip: 1000 diamonds for 5000 exp boost and 10 secs increased time
Cowhide: 3000 diamonds for 14000 exp boost and 25 secs increased time
Legacy Whip: 6000 Diamonds for 26000 exp boost and 45 secs increased time
Stromedge Whip: 10000 Diamonds for 40000 exp boost and 60 secs increased time
(These are the costs right after purchase of the Prison. You can earn up to 500 diamonds worth of credit by torturing prisoners so the costs shown to you may be lower)

How to get the best bang for your buck: The study of Joe and Bob
If you are not planning to upgrade directly to the Stormedge Whip, then the following process will allow you to maximize your benefits until you have achieved the upgrade you were looking for.

I'd like you all to meet Joe. Joe plays 6 days a week (one day strictly for the family) and tortures an average of 30 prisoners per day. He wants to upgrade to the Soft Whip and has already earned the 500 free credits, so he directly buys the whip for 500 diamonds. In return for that 500 diamonds, over the next 12 days he earns an additional 1.8 million exp and been a minor annoyance to his enemies. Not bad.....but not as good as it could be.

You see, Joe has a friend named Bob. Bob also plays 6 days a week and tortures 30 prisoners per day. He has earned the 500 free credit towards the whip upgrade as well. Instead of purchasing the Soft Whip directly, he "trials" the Stormedge Whip each day for 12 days for 40 diamonds per day for a cost of 480 diamonds. Over the course of those 12 days, he gains 14.4 million additional exp and been a much more annoying force to his enemy. Since the "trial" purchases counted towards Bob's "upgrade torture" bar (the same bar you can earn up to 500 credits on), he may now also finish the upgrade to the soft whip for only 20 diamonds making his total diamond cost for those 12 days 500 diamonds (just like Joe).

Results: Both Joe and Bob spend 500 diamonds in the end, but Bob gains 12.6 million more exp for his diamonds and the pleasure of knowing he made other players wait longer to get back into the fight. By continuing to do this, you can earn significantly more exp than you would have by directly upgrading (to anything bu the Stormedge that is), while also potentially making the costs of upgrading the whip seem more acceptable (still the same, but 500 all at once versus 40 spent 12 times gives a different perception).