solid state integrateds that will hold their value

If the choice was only the Rowland or the YBA, I would go with the Rowland. Steady ownership with a good history of servicing non-current models. The Concentra and Concentra II do sound different so depending upon your loudspeakers you might prefer one over the other. I currently own a Rowland 112 power amp (the amplifier circuit use in the Concentra II) and once owned a Concentra and have achieved very good imaging and depth portrayal with either.

You mean nominal value. Right? No discounting inflation.

Anyway, if you loose a bit, take it as if you were renting the amp.

if you can come across a simaudio i7 you will find it holds it's value well. it is a fine amp on all counts.

I would add the Vitus SIA-025 class A integrated. These lovely integrateds rarely appear on A'gon for sale, and are quickly snapped up for good reason. The SIA-025 is a true balanced, dual mono, 25 Watt class A amp which uses an efficient Vitus-designed UI-core potted "floating" transformer with separate windings for the left & right channels. The preamplifier stage is made from one single "buffer" module which is also used in the SL-102.. so .. really good, whilst the output stage is drawn from the SM-010 mono amps. The Vitus in every respect is the best integrated amp i've owned by a fair margin. Btw, the SIA-025 was updated in early Q1, 2012 which optimized multiple areas of the amp - but with most focus on the modules in both pre and power amp part. Basically it gives a bit more of everything - higher resolution, better power handling.

Most gear bought second hand should maintain it's value. I have used a good number of integrated SS amps in the past. Of the ones mentioned above, my favourite would be the Lavardin IT, with the proviso that it is'nt that powerful, you need the right, easy to drive speakers.

To name a few other manufacturers with a fine reputation and that has to be the main determinent of maintaing value, I would suggest Gamut, Luxman and Accuphase. All make fine amps I would happily live with and have a reputation of being long lived and reliable, also a prerequisite for maintaining value