To your experience, which 8051 in circuit emulator is giving faithful result, yet low cost (<$10K)? I am using Philips 8xC58 family microcontrollers. Thanks.
An low-cost alternative for standard 40-pin DIP and 44-pin PLCC 8051 devices is the SoftICE from SST that connects directly to the µVision2 Debugger. See: http://www.keil.com/pr/sst_020315.htm