Complex sentence: It is of note that many German cuckoo clock manufacturers, registered with VDS certification, also offer battery powered quartz movement cuckoo clocks to cater for demand of such clocks that are almost always markedly less expensive and require less servicing for the end user.
Split into simpler sentences: It is of note that even German cuckoo clock manufacturers registered with VDS certification also produce battery powered quartz movement cuckoo clocks. These clocks are less expensive and require less servicing for the end user.