If you order the standard parts according to the sources listed there, you must expect about 195 euros including VAT
and shipping costs. If you order the special & small parts as a kit from me, 100 Euro including
shipping costs will be added. Sales tax does not apply to you, because I am registered as a small entrepreneur (Kleinunternehmer) according to §19 Abs. 1 UStG. In total the parts for the alarm
clock cost about 295 Euro.
Depending on your experience and tooling, you have to expect about 30 to 50 hours of working time. Including the time for shopping research, ordering, preparation and soldering of the display and control elements, processing of housing and lower front panel, assembly of the board, assembly of all parts, software installation, adjustment of constants, function test, wall mounting.