1815 is the entry level Lange. Despite of a relatively lower price, the 1815 is an excellent well-made and finished piece, a refined dress watch and a good value in its catagory (together with comparable models from PP, VC, AP and Breguet).
The current European list price of 1815 manual-winding gold version (the cheapest version) is EURO 8800。The PT version costs around 12800 EURO.