I didnt pay for mine. 1 year bond reducing at $1000/month. Seemed like a fair way to do it. Current employer put me through citation X school which costs close to 40k, no bond just a handshake agreement. If you leave early good luck on getting another decent gig soon.
If you are aiming for the corporate world in particular and you pay for an endorsement you may shoot yourself in the foot, this practice is not respected and will decrease your chances of getting the gig (at a reputable operator anyway). As said before its the cost of doing business and companies hire the person not the endorsement.