In this paper, we propose a new wavelength converter placement scheme called Adaptive First Load Priority, useful for designing and planning of optical networks with sparse-partial wavelength conversion architecture. The adaptive FLP is an extension of the FLP (First Load Priority) placement scheme proposed by authors in a previous work [13]. Initially, we provide a performance evaluation of FLP. Comparing to others wavelength converter placement schemes proposed in the literature like XC scheme [5], our results show that FLP achieves the best performance at all scenarios studied, very close to that one achieved with a full-complete wavelength conversion architecture. However, we could observe that, after a certain threshold, just adding moreWavelength Converter Routers (WCR) with the FLP scheme may not have enough improvement in network performance that justifies a higherWCR cost. The Adaptive First Load Priority scheme was conceived in order to minimize the amount of WCRs used by FLP scheme, improving its cost benefit. A cost-benefit (ratio gain) study showing a superior performance of Adaptive FLP scheme is presented.