Yes, for a lot of services you just need to look at the ROI - what's the risk of your system failing due to scaling, what's the consequences of it failing, what's the likelihood of that happening; how much will it cost to get load tests up and running (both in terms of human engineering effort and computing cost to generate and handle the load). For us, we thought the likelihood was very low... but the consequences were a multimillion dollar outage... yikes! The good news is the engineering cost of load tests will generally get amortized over many years those tests will hopefully serve you (plus or minus maintenance!). Happy Load Testing!