According to my Brother a senior surgeon in USA, following is advise:

For lab work like mouse retina dissection, having precise and durable micro-scissors is crucial. F.T.S. 15004-8 is known for its high quality, but if you're looking for alternatives that are more affordable, there are several brands and factors to consider.

Popular Brands:

Dumont: Known for their precision, Dumont scissors are used in various fine dissection tasks. They offer both straight and curved blades, and while they are not the cheapest, their durability and sharpness make them a good investment in the long run.

Sable & Ziegler: Another high-quality brand that offers curved and straight micro-scissors. They are often a bit more affordable than Dumont but still maintain excellent performance for delicate dissections.

Eppendorf: Eppendorf’s micro-scissors are designed specifically for delicate biological dissections and are slightly more affordable. Their quality is often on par with the premium brands like Dumont but can be more accessible for lab budgets.

Vannas: Vannas are very popular in the field for micro-dissections, offering both straight and curved models. They're fairly affordable and long-lasting, often recommended for procedures like yours.

Mandel: Offers cost-effective options that perform well in tasks like retina dissection. They're a great alternative if you're looking for something more affordable without sacrificing too much precision.

Blade Type (Straight vs Curved):

Straight Blades: These are ideal for making clean, precise cuts where you need a flat edge. They're better for cutting through flat tissues or for more controlled dissection.

Curved Blades: Curved scissors allow for more delicate and precise cuts around tight areas or when working on circular or curved structures like retina. Many labs prefer curved blades for tasks like retina dissection because they offer better maneuverability in confined spaces.

Affordability:

While high-end brands like Dumont and Sable & Ziegler can be expensive, there are several affordable alternatives that can still meet your needs for mouse retina dissection. Brands like Eppendorf and Vannas often offer scissors that are priced competitively and still provide excellent quality and precision.

since you want only one as standby or replacement "Bulk Purchasing" options is ruled out.

Please check if suppliers offer discounted price for academic purposes.