If taking factory delivery of a new coach a private, i.e. third-party, you're needing to have a private (i.e. third-party) inspection of the coach commissioned by you (as buyer) should not be necessary as all systems/components will be new and covered by the Manufacturer's limited warranty.
The factory delivery of your new coach should and will include a Pre-Delivery Inspection (PDI) to be performed by a dedicated and assigned factory PDI tech that will serve to confirm all systems and components are operating as designed, ensure that there are no cosmetic flaws, i.e. paint, furnishings, upholsteries, cabinetry, electronics, etc. , and ensure onsite repair of any faults or flaws discovered at the time of the PDI is completed prior to you taking final delivery. The PDI should also provide you with a comprehensive "hands-on" orientation and instruction by the Factory PDI tech on the operation and use of all systems and components to include answering any/all questions you may have. You will most certainly have a lot of questions and the PDI tech should be able to answer them all as well as provide you with instructions.
Prior to taking delivery, (i.e. now) you should reach out to and speak with your Dealer or Factory sales representative and ask them to explain to you what the factory PDI process will be and how its going to work. In the event you still feel that you will need to have a private pre-purchase inspection performed, there are numerous inspection companies (and individuals) in the public sector that offer such services. One of mention is RV Inspection Connection (rvinspectionconnection.com) who employs only NRVIA certified inspectors and specialize in performing comprehenisive "on-site" inspections. Their inspectors are also bound by non-conflict agreements whereby they only represent the client (i.e. you). The cost will depend upon a number of variables, i.e. type of coach, location where the inspection is to take place, and availability of an inspector in the chosen area.
It may also be helpful to you to obtain a PDI check-list from your Dealer or Factory sales rep. ahead of taking delivery so that you can see what all the PDI includes. Having such information will help you develop your own list of questions and aid you in doing your own inspection at the time of taking delivery.
Also, since it will be your first coach, don't forego giving some thought to taking a professional RV Driving course ahead (or at the time of) your purchase. The courses are well worth the small investment in terms of building confidence and learning practical safe driving techniques that will continue to pay "dividends".
Hope this helped.
Finding The Roads That Await Us
Rick & Lydia Williams
2018 Newmar Essex 4553
NKK Member 21619 / FMCA Member 465836