If you really like to play your music loud, depending on your speakers, 15 watts per channel may not be enough power. If you don't need an AM/FM tuner then consider one of the Marantz integrated amplifiers. The Marantz 1060 at 30 watts per channel or the 1070 at 35 watts per channel would be good choices.
The 1070 in particular is very conservatively rated and is capable of delivering plenty of clean undistorted power. This amplifier is rated at 35 watts per channel, 20~20Khz at 8 ohms with no more than 0.3% distortion. When the 1070 amplifier was tested by High Fidelity magazine in March, 1975 the amplifier delivered more than 50 watts (51/54 watts for the Left and Right channels, respectively) continuous RMS power @ 8 ohms at clipping.
Intermodulation distortion measured 0.07% @ 50.4 watts output at 8 ohms and 0.17% @ 66.5 watts at 4 ohms. The reviewer concluded that Marantz could have justifiably rated the amplifier at 45 watts per channel and still have met the stated 0.3% distortion specification.
Damping factor measured 66 and signal to noise ratio was 70db (phono) and 92db for the other inputs.
For the Left and Right channels respectively the measured total harmonic distortion at 35 watts was <0.034/0.040%. At half power (17.5 watts), the total harmonic distortion measured <0.029/0.045%. At 1/10th power (0.35 watt) the total harmonic distortion measured (0.049/0.061%). This last distortion rating is of interest for headphone use, as it is unlikely that any dynamic headphone except the AKG K1000 phones would ever require more power than 1/3rd watt.
Either the 1060 or 1070 amplifier can be purchased used for between $75 and $130 so they are within your price range.