I don't know how you want to use your repeater, or how much power out you need, but RETEVIS makes a portable repeater that has it's own duplexer built in, and is tunable from 136 to 174MHZ. It is advertised as a 10 watt unit but by the time that 10 watts goes through the duplexer you loose about 3 Db for an output of 5 watts. The cost is $364.99.
If you go to youtube and type in NOTARUBICON, there is a guy that has done a demonstration of the unit and explains all of the hook ups. I will let you look up the video to hear more about duty cycles and usage. The guy is kind of non ham and is a GMRS guy. If you can stand to listen to him, the video has good info. If 5 watts won't cut it you may be able to add an amplifier. You said you wanted cheap so this could be an option. Go to retevis.com for more info.
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